Hydroformylation process using novel phosphite-metal catalyst system

Abstract

This invention relates to a hydroformylation process for preparing an aldehyde, which comprises reacting an olefin with hydrogen and carbon monoxide in the presence of a catalyst solution comprising of rhodium, a hydroformylation solvent and a chlorophosphite compound having the general formula ##STR1##

We claim: 
     
       1. A process for preparing an aldehyde which comprises contacting an olefin, hydrogen and carbon monoxide with a solution of a catalyst system comprising rhodium, a chlorophosphite compound having the formula ##STR14## wherein R 7  represents hydrogen, halogen or C 1  to C 12  alkyl; R 8  represents halogen, C 1  to C 12  alkyl or C 1  to C 12  alkoxy; r is 0, 1 or 2; and X is a group having the formula ##STR15## wherein R5 is hydrogen, alkyl or aryl; and R6 is hydrogen or alkyl; and a hydroformylation solvent; wherein the ratio of gram moles chlorophosphite ligand to gram atoms rhodium is at least 1:1. 
     
     
       2. A process for preparing an aldehyde which comprises contacting an olefin, hydrogen and carbon monoxide with a solution of a catalyst system comprising rhodium, a chlorophosphite compound of the formula ##STR16## wherein R 7  represents hydrogen, chloro or C 1  to C 4  alkyl; R 8  represents chloro, C 1  to C 4  alkyl or C 1  to C 4  alkoxy; r is 0, 1 or 2; and X is a group having the formula ##STR17## wherein R 5  is hydrogen, alkyl or aryl; and R 6  is hydrogen or alkyl; and the olefin is a mono-α-olefin of 3 to 8 carbon atoms; and wherein the ratio of grams moles of chlorophosphite ligand to gram atoms rhodium is at least 1:1; and the process is carried out at a temperature of 50 to 135° and the normal to iso ratio of the aldehyde product is controlled by varying the partial pressure of carbon monoxide in the reactor gas between 3 and 8 bara. 
     
     
       3. Process according to claim 2 wherein the concentration of rhodium in the solution is in the range of about 30 to 300 mg per liter; the chlorophosphite ligand is 2,2'-methylidenebis(3,4,6-trichlorophenyl) chlorophosphite; the ratio of gram moles chlorophosphite ligand to gram atoms rhodium is about 15:1 to 50:1; the olefin is a mono-α-olefin of 2 to 10 carbon atoms; and the process is carried out at a temperature of about 50 to 135° C. at a pressure in the range of ambient to about 36 bars absolute.